This week, we review the top religion stories of 2015--from gay marriage, to ISIS, to Pope Francis' climate message. Then, a new biography gives heretofore unpublished insights into the life and faith of the celebrated Sister Joan Chittister.

The new chief pastor of a church once called the 'church of the white establishment' is Michael Curry, an African-American bishop from North Carolina. And a new film documents the lives of 8 chaplains.